1. Field of the Invention
This invention relates to an apparatus for applying surgical clips to body tissue during laparoscopic or endoscopic procedures, and more particularly, to a surgical clip applier adapted to apply fully crimped clips as well as a partially formed clip during surgical procedures.
2. Description of Related Art
In laparoscopic and endoscopic surgical procedures, a small incision is made in the patient's body to provide access for a robe or cannula device. Once extended into the patient's body, the cannula provides an access port which allows insertion of various surgical instruments through the cannula for acting on organs, blood vessels, ducts, or body tissue far removed from the incision. Often during these procedures, it is necessary to apply hemostatic clips to blood vessels or various ducts to prevent the flow of body fluids therethrough during the procedure. Many limes, the surgical procedure may necessitate the temporary implantation of shunts or tubes into ducts or vessels. Such procedures, such as gall bladder surgery, often require the placement of a shunt into the ducts during excision of the organ. To secure the shunt, a clip must be applied which is partially closed so as to avoid occluding the shunt. While instruments for performing surgical clip application are known in the art, none provide indication of the successful application of a partially crimped clip, such as is necessary to secure the shunt. Fully crimping a clip over a shunt will obviously occlude the shunt and defeat its purpose.
One clip applier known well in the art is described in U.S. Pat. No. 5,084,057, the disclosure of which is incorporated herein by reference. This instrument includes a mechanism for sequentially advancing a plurality of surgical clips towards a pair of distal jaw members. Through actuation of handle structure, the jaw members are closed to advantageously crimp the clip. The instrument does not provide an indication of the spacing between the jaws during the closing of the jaw members, other than through visual examination of the jaw members through an endoscope. Thus, when attempting to detachably secure a shunt to tissue, e.g., for cholangiography, it can be difficult to ascertain whether the jaw members have closed to an appropriate gap for securing the shunt.
Furthermore, many instruments now incorporate ratchet mechanisms to prevent inadvertent opening of the handles and jaws until the clip is fully crimped, requiring a full closing stroke. Thus, the instruments are not designed to deliver a partially crimped clip.
It has been common for clip appliers to rely on friction to capture a clip between the jaw members following advancement of the clip from the clip supply. Accordingly, the jaw members are constructed so as to have a gap between the crimping surface of each jaw member which is slightly less than the distance between the legs of a clip, so that the clip is slightly pinched between the jaws to hold the clip therein.
Another method of maintaining the clip within the jaws is to machine the crimping surfaces of the jaw members to have a clip accepting slot. However, this increases cost and requires precision during the machining process to provide the proper dimensions for end use. The jaw members are typically a costly item since they are machined from a single piece to form the crimping surfaces.
In view of this, it has been known to fabricate the jaw members separately, and then to assemble the jaw mechanism in the clip applying instrument. However, in instruments such as those disclosed in U.S. Pat. Nos. 5,047,038; 4,246,903 and 4,228,895, the jaws are hinged at a pivot point and do not provide reliable securements and accurate camming.
Should the jaw members be improperly gapped or aligned, the clip tends to fall out of the jaws, and potentially, into the patient's body. In addition, the clip advancement mechanism may not properly orient the clip if the jaws are not properly spaced. While some instruments may provide some clip alignment feature or clip stop mechanism, these are typically internal mechanisms which operate in conjunction with the clip supply, not the jaw mechanisms, such as disclosed in U.S. Pat. Nos. 5,192,288 and 4,616,650. Finally, should the clip become dislodged, or slightly deviate off-line, there is no provision in the prior art for holding or guiding the clip into the jaws. While some instruments may provide tabs to align the clip at the clip supply, such as disclosed in U.S. Pat. No. 4,492,262, there is no provision to support the clip outside the instrument at the jaws.
It is also common, due to the restricted space at the surgical site in which the clip appliers are used, that at times a clip may be applied which is interfered with by a clip that has previously been applied, leading to a splaying of the jaws beyond the original gap between the jaw members. Depending on the strength of the jaw members, this may lead to an improper feeding of a subsequent clip to the jaws, resulting in potential instrument malfunction.
It has been long known to provide instruments having a means for rotating the instrument with respect to its longitudinal orientation, typically through the provision of a rotation collar positioned at the juncture between the handle and elongated body portions of the instrument. Despite the multitude of prior art rotatable surgical instruments, a need exists to optimize the rotation collar to provide for more facile rotation capabilities.
Those skilled in the surgical arts have recognized the need for a clip applicator which may be used in endoscopic or laparoscopic procedures such as gall bladder operations which is configured to partially close and release a clip to secure shunts during the procedure. In addition, a need exists for a clip applier which accurately advances and holds a clip in the jaw mechanism and which prevents splaying of the jaws in the event of a clip over clip application. An instrument is also needed which provides a visual indication of the position of the jaw mechanism, and may also provide an audible and tactile indication. An instrument is also needed which prevents feeding of a clip in the event the jaws are not fully opened, as well as an instrument which provides for facile rotation of the instrument's body portion.